[Zn5(PO4)(HPO4)4(Hbpy)2(bpy)][H2PO4]·H2O: a novel inorganic–organic metal-phosphate framework showing an unprecedented (3,4)-connected (4·62)6(4·62·103)2(64·102)2 topology and the coexistence of various phosphates

Abstract

Via solvo(hydro)thermal synthesis, a novel three-dimensional inorganic–organic Zn(II)-phosphate framework, namely [Zn₅(PO₄)(HPO₄)₄(Hbpy)₂(bpy)][H₂PO₄]·H₂O (1, bpy = 4,4′-bipyridine), was obtained. The connectivity of Zn(II) ions, PO₄³⁻, and HPO₄²⁻ groups creates a 2-D anionic layer with a previously unobserved (4·6²)₈(6⁴·10²)₂ topology matrix in the ab-plane, which is further supported by partial bpy ligands, resulting in the overall 3D charge-positive layer-pillared framework with an unprecedented (3,4)-connected (4·6²)₆ (4·6²·10³)₂(6⁴·10²)₂ topology. To balance the net cationic charge of the framework, an extra framework anion like H₂PO₄⁻ is encapsulated in the void space, in which guest water molecules are also located.